Hostname: page-component-848d4c4894-x5gtn Total loading time: 0 Render date: 2024-05-02T14:10:27.062Z Has data issue: false hasContentIssue false
  • English
  • Français

Trans-tegumental absorption of L-alanine and L-leucine by a monogenean, Diclidophora merlangi

Published online by Cambridge University Press:  06 April 2009

D. W. Halton
D. W. Halton
Affiliation:
Department of Zoology, The Queen's University, Belfast BT7 1NN
Get access Rights & Permissions [Opens in a new window]

Summary

An in vitro investigation has been made of the relative roles of the gut and tegument in the absorption of the neutral amino acids L-alanine and L-leucine by a marine fish-gill parasite, Diclidophora merlangi. The use of ligatures to preclude oral ingestion of trace-labelled medium has proved inadequate, invariably damaging the tegument, as revealed by stereoscan electron microscopy, and resulting in artifactual levels of absorption. Three alternative procedures have given consistently reliable data on the route of entry of low molecular weight substrates. (1) Ultrastructural examination of worms previously incubated in electron-dense cationic tracers has shown that, in vitro, there is no oral intake of sea water. (2) The suspending of worms in trace-labelled medium with the mouth out of the medium and comparing amino acid uptake with that of worms totally immersed in medium has revealed no statistically significant difference in the absorption levels. (3) Application of section (freeze-dried) auto-radiography to detect diffusible isotope has demonstrated directly transtegumental absorption of a neutral amino acid. It is concluded from these experiments that Diclidophora has a tegumental transport system for absorbing certain neutral amino acids, and whilst, clearly, the worm is sanguinivorous and digests blood in a well-developed gut, it may also be capable of supplementing this diet with low molecular weight organic nutrient absorbed directly from sea water via the tegument.

Type
Research Article
Information
Parasitology , Volume 76 , Issue 1 , February 1978 , pp. 29 - 37
Copyright
Copyright © Cambridge University Press 1978

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Asch, H. L. & Read, C. P. (1975). Transtegumental absorption of amino acids by male Schistosoma mansoni. Journal of Parasitology 61, 378–9.Google Scholar
Bélanger, L. F. (1961). Staining processed radioautographs. Stain Technology 36, 313–17.CrossRefGoogle ScholarPubMed
Chappell, L. H. (1974). Methionine uptake by larval and adult Schistosoma mansoni. International Journal for Parasitology 4, 361–9.CrossRefGoogle ScholarPubMed
Halton, D. W. (1974). Hemoglobin absorption in the gut of a monogenetic trematode, Diclidophora merlangi. Journal of Parasitology 60, 59–66.Google Scholar
Halton, D. W. (1975). Intracellular digestion and cellular defecation in a monogenean, Diclidophora merlangi. Parasitology 70, 331–40.CrossRefGoogle Scholar
Halton, D. W. (1976). Nutrition in monogeneans. Parasitology 73, 21–xxii.Google Scholar
Halton, D. W. & Arme, C. (1971). In vitro technique for detecting tegument damage in Diclidophora merlangi: possible screening method for selection of undamaged tissues or organisms prior to physiological examination. Experimental Parasitology 30, 54–7.CrossRefGoogle ScholarPubMed
Hines, W. J. W. (1969). An in vitro effect of insulin on glycogen levels in the common liver fluke, Fasciola hepatica (Linnaeus, 1758), Comparative Biochemistry and Physiology 28, 1443–7.Google Scholar
Isseroff, H. & Read, C. P. (1969). Studies on membrane transport. VI. Absorption of amino acids by fascioliid trematodes. Comparative Biochemistry and Physiology 30, 1153–9.Google Scholar
Isseroff, H. & Read, C. P. (1974). Studies on membrane transport. VIII. Absorption of monosaccharides by Fasciola hepatica. Comparative Biochemistry and Physiology 47A, 141–52.CrossRefGoogle Scholar
Jørgensen, C. B. (1976). August Pütter, August Krogh and modern ideas on the use of dissolved organic matter in aquatic environments. Biological Reviews 51, 291–328.CrossRefGoogle Scholar
Llewellyn, J. (1956). The host-specificity, micro-ecology, adhesive attitudes, and comparative morphology of some trematode gill parasites. Journal of the Marine Biological Association, U.K. 35, 113–27.CrossRefGoogle Scholar
Lumsden, R. D. (1975). Surface ultrastructure and cytochemistry of parasitic helminths. Experimental Parasitology 37, 267–339.CrossRefGoogle ScholarPubMed
Lyons, K. (1972). Ultrastructural observations on the epidermis of the polyopisthocotylinean monogeneans Rajonchocotyle emarginata and Plectanocotyle gurnardi. Zeitschrift für Parasitenkunde 40, 87–100.Google Scholar
McCrea, S. R. (1976). Comparative studies of amino acid absorption in bivalve gill in relation to environmental factors. Ph.D. thesis. The Queen's University of Belfast.Google Scholar
Mansour, T. E. (1959). Studies on the carbohydrate metabolism of the liver fluke Fasciola hepatica. Biochimica et Biophysica Acta 34, 456–64.Google Scholar
Morris, G. P. & Halton, D. W. (1971). Electron microscope studies of Diclidophora merlangi (Monogenea: Polyopisthocotylea). II. Ultrastructure of the tegument. Journal of Parasitology 57, 49–61.CrossRefGoogle Scholar
Nollen, P. M. & Nadakavukaren, M. J. (1974). Observations on ligated adults of Philophthalmus megalurus, Gorgoderina attenuata and Megalodiscus temperatus by scanning electron microscopy and autoradiography. Journal of Parasitology 60, 921–4.CrossRefGoogle Scholar